[quote=

You should try some Cutting Edge Bullets .458 258 GR.SOCOM Brass Flat Base Raptor...they are deadly will shoot flatter and little less recoil they been used on a bunch of North American game and African up to cape buffalo ...Lil'Gun powder first choice second choice Enforcer should be a good powders close to a full case don't compress powder... seat bullet with two bands in case to get more capacity....should get close to 2400 fps....

https://cuttingedgebullets.com/452-258gr-flat-base-raptor

Also a great bullet Cutting Edge Bullets. 458 260gr Rifle Maximus

https://cuttingedgebullets.com/458-260gr-rifle-maximus-50ct

[/quote]
Might give those a try.Looks like they would turn that into a 275 yd gun.